Nickel Sulfate Series With The Crystal Structure, Growth And Performance | | Posted on:2005-09-29 | Degree:Doctor | Type:Dissertation | | Country:China | Candidate:X X Zhuang | Full Text:PDF | | GTID:1111360182465417 | Subject:Physical chemistry | | Abstract/Summary: |  PDF Full Text Request | | This thesis reports on the synthesis, structures and characteristics of new nickel sulfate complexes,(NH4)2Ni(SO4)2·6H2O,FeNi(SO4)2·12H2O, CoNi(SO4)2·12H2O, Mn0.19Ni0.81(SO4)2·7H2O, Zn0.24Ni0.76(SO4)2·7H2O as new ultraviolet materials. Specific preparations of these new materials by compounding reaction method were presented. New single crystals (NH4)2Ni(SO4)2·6H2O, FeNi(SO4)2·12H2O and CoNi(SO4)2·12H2O were grown by decreasing temperature method and optical grade crystals with size upto 1 centimeter were obtained. Structures and powder diffraction spectra of these new crystals were determined by X-ray diffraction method for specification of solid phase and identification of crystals. Thermal properties of new crystals were tested by TGA method. The dominant features deal with structure of complexes involved NiSO4·6H2O and K2Ni(SO4)2·6H2O crystals additional were discussed. Studies on the growth mechanisms of (NH4)2Ni(SO4)2·6H2O crystal were presented. Observations of the growth on face (100),(011) and (110) in static or stirring solutions at different supersaturation were recorded. On the combination of BCF spiral growth model and the fundamental of Bennema's modification, empirical kinetic formulas of crystal growth were deduced and reaction energies at different growth processes were evaluated. A new design on solution density measurement described as magnetic weigh method (MWM) was introduced. Rates of mass deposition vs. concentration were calculated accurately for the investigation of crystallizing mechanisms. With reference to Nielsen's classification, contributions of spiral growth and diffusion or transport adsorption at crystal surface were analyzed. The transmittance spectra of (NH4)2Ni(SO4)2·6H2O,FeNi(SO4)2·12H2O, CoNi(SO4)2·12H2O, Mn0.19Ni0.81(SO4)2·7H2O, Zn0.24Ni0.76(SO4)2·7H2O crystals and solutions at region 200-1500nm were measured. Absorption peaks at 8500cm-1,14500 cm-1,25600cm-1 caused by 3 A2 g →3T2g, 3 A2 g →3T1g(F), 3 A2 g →3T1g(P) d-d transitions were verified, respectively. In order to explain the transitions based on crystal field theory, crystal field parameter Dq and Racah parameter B of these samples were calculated. Also energy splittings of all terms of d8 configuration were obtained. It was found in the experiment that a weak peak at 35400cm-1 was caused by absorption of d electrons in Ni(H2O)62+ group and the correspondent term was clarified.
| | Keywords/Search Tags: | (NH4)2Ni(SO4)2·6H2O crystal, FeNi(SO4)2·12H2Ocrystal, CoNi(SO4)2·12H2O crystal, Mn0.19Ni0.81(SO4)2·7H2O crystal, Zn0.24Ni0.76(SO4)2·7H2O crystal, UV crystal, Spiral growth, Decreasing temperature method, Crystal field theory | | PDF Full Text Request | Related items |
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